The high price and toxicity of ionic liquids(ILs) have limited the design and application of supported ionic liquid membranes(SILMs) for CO_2 separation in both academic and industrial fields. In this work, [Choline][...The high price and toxicity of ionic liquids(ILs) have limited the design and application of supported ionic liquid membranes(SILMs) for CO_2 separation in both academic and industrial fields. In this work, [Choline][Pro]/polyethylene glycol 200(PEG200) mixtures were selected to prepare novel SILMs because of their green and costeffective characterization, and the CO_2/N_2 separation with the prepared SILMs was investigated experimentally at temperatures from 308.15 to 343.15 K. The temperature effect on the permeability, solubility and diffusivity of CO_2 was modeled with the Arrhenius equation. A competitive performance of the prepared SILMs was observed with high CO_2 permeability ranged in 343.3–1798.6 barrer and high CO_2/N_2 selectivity from 7.9 to 34.8.It was also found that the CO_2 permeability increased 3 times by decreasing the viscosity of liquids from 370 to38 m Pa·s. In addition, the inherent mechanism behind the significant permeability enhancement was revealed based on the diffusion-reaction theory, i.e. with the addition of PEG200, the overall resistance was substantially decreased and the SILMs process was switched from diffusion-control to reaction-control.展开更多
Designing novel lubricants with easily customized structures,devisable compositions,and simple and economic synthesis over traditional lubricants is critical to fulfilling complex applications,prolonging machine lifet...Designing novel lubricants with easily customized structures,devisable compositions,and simple and economic synthesis over traditional lubricants is critical to fulfilling complex applications,prolonging machine lifetime,and saving energy.Deep eutectic solvents(DESs),which show tunable composition,adjustable structure,easy fabrication,and environmental friendliness,are promising candidates for variable and complicated lubricants applications.To promote the use of DESs as lubricants,a series of PEG200-based DESs with active heteroatoms were fabricated to tailor the tribological performance via tribo-chemistry.Thereinto,PEG200/boric acid(BA)DES shows optimal lubrication performance by forming tribo-chemical reaction film composited of B2O3,iron oxides,and FeOOH,and PEG200/thiourea(TU)DES displays abrasive wear-reducing property by producing FeS tribo-chemical film.Given the excellent abrasive wear-resistance of PEG200/TU DES and friction reduction of PEG200/BA DES,ternary PEG200/BA/TU DESs,composited of PEG200/TU DES and PEG200/BA DES,are first exploited.The ternary DESs possess superior wettability and thermal stability,which render them potential lubricants.Tribological tests of the ternary DESs demonstrate that synergistic lubrication is achieved by forming a transfer film consisting of FexBy,BN,B2O3,and FeS.Wherein FexBy,BN,and B2O3 increase load bearing of the film,and FeS mitigates severe abrasive wear.The proposed design philosophy of novel DESs as lubricants opens up a unique realm that is unattainable by traditional DESs lubrication mechanisms and provides a platform to design next-generation DESs lubrication systems.展开更多
Preparation and characterization of the YBCO superconducting films by chemical solution route with polyethylene glycol (PEG200) and Cu(NO3)2 as precursors are presented. It was found that PEG200 and sucrose were novel...Preparation and characterization of the YBCO superconducting films by chemical solution route with polyethylene glycol (PEG200) and Cu(NO3)2 as precursors are presented. It was found that PEG200 and sucrose were novel chelates and Cu (NO3)2 was an alternative precursor for the preparation of YBCO superconducting film by chemical solution route. The precursor solution was prepared by mixing yttrium trifluoroacetate, barium trifluoroacetate, and copper nitrate in solvent of methanol with chelates including PEG200 and sucrose. YBCO films were prepared by coating the precursor solution on LaAlO3 single crystal substrate, following vacuum drying, rapid calcining, firing and oxygen annealing. The prepared films were characterized by optical microscope (OM), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that films were crack-free and homogeneous, stronger tendency of (00l) texture, uniform with less pore, pure c-axis orientation. The films showed good superconducting properties, with Tc of 90 K and critical current density (Jc) of 1 MA/cm2 (77 K, 0 T). This work demonstrates that the developed method is a promising method for preparation of YBCO superconducting film which has a fine superconducting characterization with advantages of simple and rapid.展开更多
基金Supported by the National Basic Research Program of China(2013CB733501)the National Natural Science Foundation of China(21136004,21176112,21476106,and21428601)+1 种基金Specialized Research Fund for the Doctoral Program of Higher Education(No.20133221110001)the Project of Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘The high price and toxicity of ionic liquids(ILs) have limited the design and application of supported ionic liquid membranes(SILMs) for CO_2 separation in both academic and industrial fields. In this work, [Choline][Pro]/polyethylene glycol 200(PEG200) mixtures were selected to prepare novel SILMs because of their green and costeffective characterization, and the CO_2/N_2 separation with the prepared SILMs was investigated experimentally at temperatures from 308.15 to 343.15 K. The temperature effect on the permeability, solubility and diffusivity of CO_2 was modeled with the Arrhenius equation. A competitive performance of the prepared SILMs was observed with high CO_2 permeability ranged in 343.3–1798.6 barrer and high CO_2/N_2 selectivity from 7.9 to 34.8.It was also found that the CO_2 permeability increased 3 times by decreasing the viscosity of liquids from 370 to38 m Pa·s. In addition, the inherent mechanism behind the significant permeability enhancement was revealed based on the diffusion-reaction theory, i.e. with the addition of PEG200, the overall resistance was substantially decreased and the SILMs process was switched from diffusion-control to reaction-control.
基金support from the National Natural Science Foundation of China(Nos.52175190 and 51805455)and the Fundamental Research Funds for the Central Universities(No.2682021CX117).
文摘Designing novel lubricants with easily customized structures,devisable compositions,and simple and economic synthesis over traditional lubricants is critical to fulfilling complex applications,prolonging machine lifetime,and saving energy.Deep eutectic solvents(DESs),which show tunable composition,adjustable structure,easy fabrication,and environmental friendliness,are promising candidates for variable and complicated lubricants applications.To promote the use of DESs as lubricants,a series of PEG200-based DESs with active heteroatoms were fabricated to tailor the tribological performance via tribo-chemistry.Thereinto,PEG200/boric acid(BA)DES shows optimal lubrication performance by forming tribo-chemical reaction film composited of B2O3,iron oxides,and FeOOH,and PEG200/thiourea(TU)DES displays abrasive wear-reducing property by producing FeS tribo-chemical film.Given the excellent abrasive wear-resistance of PEG200/TU DES and friction reduction of PEG200/BA DES,ternary PEG200/BA/TU DESs,composited of PEG200/TU DES and PEG200/BA DES,are first exploited.The ternary DESs possess superior wettability and thermal stability,which render them potential lubricants.Tribological tests of the ternary DESs demonstrate that synergistic lubrication is achieved by forming a transfer film consisting of FexBy,BN,B2O3,and FeS.Wherein FexBy,BN,and B2O3 increase load bearing of the film,and FeS mitigates severe abrasive wear.The proposed design philosophy of novel DESs as lubricants opens up a unique realm that is unattainable by traditional DESs lubrication mechanisms and provides a platform to design next-generation DESs lubrication systems.
基金National High Technology Research and Development Program of China ("863" Program) (2009AA03Z203)
文摘Preparation and characterization of the YBCO superconducting films by chemical solution route with polyethylene glycol (PEG200) and Cu(NO3)2 as precursors are presented. It was found that PEG200 and sucrose were novel chelates and Cu (NO3)2 was an alternative precursor for the preparation of YBCO superconducting film by chemical solution route. The precursor solution was prepared by mixing yttrium trifluoroacetate, barium trifluoroacetate, and copper nitrate in solvent of methanol with chelates including PEG200 and sucrose. YBCO films were prepared by coating the precursor solution on LaAlO3 single crystal substrate, following vacuum drying, rapid calcining, firing and oxygen annealing. The prepared films were characterized by optical microscope (OM), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that films were crack-free and homogeneous, stronger tendency of (00l) texture, uniform with less pore, pure c-axis orientation. The films showed good superconducting properties, with Tc of 90 K and critical current density (Jc) of 1 MA/cm2 (77 K, 0 T). This work demonstrates that the developed method is a promising method for preparation of YBCO superconducting film which has a fine superconducting characterization with advantages of simple and rapid.
